Post-traumatic stress disorder (PTSD) is one of the most frequently occurring disorders in persons seeking treatment for alcohol dependence (AD). Moreover, AD individuals with comorbid PTSD have poorer alcohol treatment outcomes than AD individuals with or without other psychiatric conditions. Despite the high level of comorbidity between these disorders, there is little laboratory-based research directed at understanding the mechanism(s) by which PTSD may affect important aspects of AD, such as craving. One possible mechanism may be negative emotions (e.g., fear, anxiety) experienced by individuals with PTSD when remembering or encountering aspects of a prior traumatic event (e.g., physical or sexual assault). Recently, research has shown that imaginal exposure to a personalized trauma cue increases negative emotion and alcohol craving in individuals with comorbid AD and PTSD. In addition, research has consistently demonstrated that AD only individuals respond with greater craving, for alcohol in response to negative emotional cues. Taken together, these findings suggest that reducing negative emotions may be one way to reduce craving for alcohol in individuals with comorbid AD-PTSD. One well-validated method to reduce negative emotional reactivity in PTSD populations is by exposing PTSD patients to imaginal trauma cues for an extended period of time. However, it has yet to be demonstrated that a reduction in negative emotion leads to a reduction in alcohol craving in alcoholics with PTSD. The current application is designed to fill that void by combining a laboratory-based method to assess emotion and craving with an empirically supported approach to reduce trauma-related negative emotion. Using a cue reactivity paradigm previously used with an AD-PTSD comorbid sample, we propose to assess cue-elicited craving and emotion prior to and following repeated imaginal exposure to an individualized trauma cue. Craving and emotion will be assessed by physiological arousal and self-report following exposure to trauma and alcohol cues singly and in combination. The primary aim of this project is to test if prolonged and repeated imaginal exposure to a trauma cue will modify the emotional reactivity, physiological arousal, and alcohol craving elicited by that cue. Success in demonstrating that a reduction in negative emotion leads to a concomitant reduction in alcohol craving will enhance our understanding of the relation between emotion and craving in individuals with comorbid AD-PTSD, and will provide empirical support to justify the use of imaginal trauma cue exposure treatment for AD individuals with PTSD.